Past quarrels between Washington and Delhi have become just that: past. Since the Khobragade affair plummeted relations over a year ago, diplomatic ties are on the rebound. Here's why.

U.S. President Barack Obama meets with Indian Prime Minister Narendra Modi in the Oval Office of the White House September 30, 2014 in Washington, DC. The two leaders met to discuss the U.S.-India strategic partnership and mutual interest issues. (Photo by Alex Wong/Getty Images)

What a difference a year makes.

Last January, normally robust U.S-India relations quickly frayed following the arrest of an Indian consular official in New York over visa fraud charges. Facing possible prosecution in the United States, the consular official, Devyani Khobragade, was forced to return home. The episode ignited a fierce diplomatic row between Washington and New Delhi. India cast the arrest as an affront to its national honor and took several retaliatory measures against the United States. Talk of an unprecedented breakdown and total collapse of relations was not uncommon. A consensus emerged that the U.S-India strategic partnership had sustained grave damage. Few could remember a time in recent history when bilateral ties experienced such strain.

That was then.

Now, twelve months later, diplomatic relations between the world’s oldest and largest democracies have experienced a dramatic recovery. In a sign of just how much has changed since the Khobragade affair, President Obama is scheduled to visit India next week as the chief guest of the country’s famed Republic Day celebrations. The invitation is reserved exclusively for New Delhi’s closest friends, and Obama is the first American president to receive the honor. He will also make history by becoming the first sitting U.S. president to visit India twice. The trip is a powerful demonstration of the value both countries place on preserving and cultivating a strong bilateral partnership.

This strikingly rapid transformation is the result of a variety of factors.

First, the election of a new Indian government last May provided the two countries with an opportunity for a fresh start. The opposition Bharatiya Janata Party (BJP) swept into power for the first time in a decade after inflicting a crushing electoral defeat on the governing Congress Party. Led by Prime Minister Narendra Modi, the BJP’s landmark victory injected some sorely needed momentum into struggling bilateral ties. Initially, some feared Modi’s election would only further complicate U.S.-India relations. Washington had denied his visa almost a decade earlier on the grounds that he had failed to stop communal riots in 2002 in his home state of Gujarat while serving as chief minister.

But those fears proved to be unfounded. The Obama Administration moved swiftly to embrace the new government. Meanwhile, Prime Minister Modi signaled from the outset that strengthening ties with Washington constituted a top priority, regardless of what had transpired in the past. Officials in both capitals viewed the historic election as an opportunity for both sides to start anew and put the faltering relationship back on steady ground.

Second, geopolitical considerations also weighed in favor of repairing bilateral relations. From the Indian perspective, New Delhi harbored longstanding concerns about the consequences the American withdrawal from Afghanistan would have on regional stability and its national security. Indian officials also remained leery of Washington resuscitating its fraught relationship with Islamabad at India’s expense. Decision makers in New Delhi quickly realized that maintaining ties with Washington was critical to promoting and protecting Indian security interests in the region.

Washington made a corresponding calculation. Tense relations with New Delhi would make a smooth exit from Afghanistan more difficult. American officials also hoped that India could ultimately become a net security provider in the region in the absence of Western troops.

Beyond Afghanistan, Washington recognized that U.S.-India ties also implicated ongoing efforts by the United States to curb Iran’s controversial nuclear program. The Obama Administration’s ability to maintain meaningful sanctions on Iran’s lucrative oil industry depended then—as it does now—on New Delhi’s continuing cooperation.

Together, these imperatives helped ensure that the rift created by the Khobragade controversy was not irreparable.

Third, moving past the diplomatic row and bolstering U.S.-India relations made political sense for leaders in both Washington and New Delhi. For Modi, a strong partnership with the United States would enhance his own stature at home, burnish his image abroad, and effectively help erase any lingering stigma stemming from the 2002 riots in Gujarat, where heavy anti-Muslim communal violence resulted in the deaths of about 1,000 people. His September 2014 inaugural visit to the United Stated heralded the completion of his political rehabilitation on the global stage.

For Obama, championing the U.S.-India partnership offers his administration the chance to score a badly needed foreign policy win. A series of seemingly intractable challenges abroad – including civil war in Syria, the emergence of ISIS, and a resurgent Russia – have left the president with very few options to forge a successful foreign policy legacy. The success of his outreach to Havana is too early to judge. By comparison, India offers an alluring, relatively low-risk prospect for success. The U.S.-India strategic partnership enjoys rare bipartisan support within Congress and among the American public. The president is wise to capitalize on this with his historic trip to India next week.

Viewed within this political context, it was unlikely that either leader would have allowed tensions over the Khobragade affair to persist for too long.

Fourth, and perhaps most importantly, the underlying strategic logic of the U.S.-India partnership remained unchanged despite the arrest. More than a decade ago, the two countries embarked on a multidimensional partnership based upon common interests and values. American officials regarded India as a stabilizing force and an important partner in the region that could help manage China’s own unpredictable rise and address a slate of enduring international threats. India’s middle class—among the biggest in the world—compelled greater economic cooperation. Since the early 2000s, bilateral trade is up nearly fivefold from $2.4 billion to $30 billion. A shared respect for democratic values like pluralism, secularism, and the rule of law provided an ideological basis for the relationship. Both countries recognized they could achieve far more by partnering together than they could alone.

The Khobragade arrest did not make this any less true. Although some critics contended that the resulting diplomatic row exposed the frailty of the partnership, the recovery in relations over the past year belies the assertion. Ultimately, the foundational pillars of the relationship remained unaffected by the episode. The turnaround, while not inevitable, was consistent with the overall character and trajectory of bilateral ties.

Obama’s upcoming visit to India could witness agreements on a host of different arenas, including climate change, nuclear liability, trade, and defense procurement. Both countries are eager to move the relationship forward and propel it to new heights.

Devyani Khobragade, on the other hand, is not faring so well. The consular official—hailed as a national hero upon her return home last year—is now under investigation by the Indian government for impermissibly giving media interviews about her ordeal and failing to inform authorities about her children’s U.S. citizenship. She has been stripped of her duties and cannot be posted abroad pending the outcome of these inquiries.